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Groups > linux.kernel > #1484125
| From | Pavel Machek <pavel@ucw.cz> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] leds: Introduce userspace leds driver |
| Date | 2016-09-15 14:50 +0200 |
| Message-ID | <shEh3-75Z-9@gated-at.bofh.it> (permalink) |
| References | <see9r-422-3@gated-at.bofh.it> <sf4hI-47K-35@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Hi!
> Thanks for the patch. It is very nice. I have only one minor remark
> in the code.
>
> I think that it would be good to add a documentation for this
> driver to Documentation/leds, with exemplary C program instead
> of python one. The program could poll the dev node in a loop,
> which allows to conveniently check the impact of setting particular
> triggers and all other brightness change events.
Actually, I'd say that python is fine -- it is used heavily in tools/.
But perhaps the example program should go to tools/?
> >def change_brightness(b):
> > with open('/sys/class/leds/{}/brightness'.format(name) , 'w') as f:
> > f.write(str(b))
> >
> >
> >with open('/dev/uleds', 'rb+', 0) as uleds:
> > bname = name.encode("ascii")
> > # create the leds class device
> > uleds.write(bname + b'\0' * (ULEDS_MAX_NAME_SIZE - len(bname)))
Umm. I don't see it in the kernel code. You let userspace provide a
LED name?
Where is the LED name tested for sanity? I guess there could be a lot
of fun naming a led ".." for example...
Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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Re: [PATCH] leds: Introduce userspace leds driver Pavel Machek <pavel@ucw.cz> - 2016-09-15 14:50 +0200 Re: [PATCH] leds: Introduce userspace leds driver Jacek Anaszewski <j.anaszewski@samsung.com> - 2016-09-15 17:00 +0200
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